Refuse pit



De@a 10, 1929.. R. A. FOREYSMAN 197739,135

REFUSE PIT Filed Feb. 11, 1927 sheets-sheet l Aforesman VENTOR ABY@HBK/Lm ATTORN EY Dec, 150, 929` R. A. FORESMAN 1,739,135

REFUSE PIT` Filed Feb. 11, 1927 2 Sheets-Sheet 2 WITNESSES INVENTORATTORN EY Patented i Dec. 10, 1929 UNITED STATES PATENT OFFICE ROBERT A.FORESMAN, OF MOORES, PENNSYLVANIA, ASSIGNOR T WESTINGHOUSE ELECTRIC &MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA REFUSE PITApplication led February 11, 1927. Serial No.' 167,545.

My invention relates to combustion apparatus and more particularly-toapparatus of this character which are provided with pits for thereception of refuse, and it has for an object the provision of apparatusfor mini.

mizing the premature discharge of combustible material from these refusepits.

More specifically the object of `my invention is to provide shield meansbeneath the grinder rolls commonly associated with the refuse pit andeffective to impede the sifting of line material from the refuse pit andto insure its removal therefrom only by direct action of the grinderrolls.

Apparatus embodying features of my invention is illustrated in theaccompanying drawings forming a part of this specification wherein:

Fig. 1 is a fragmentary'longitudinal section zo through a stoker showingone form of my invention as applied to a clinker pit having a singleclinker grinder roll;

Fig. 2 .is a view similar to Fig. 1 showing one form of my inventionapplied to a clinker g5 pit having double clinker grinder rolls; and,

Fig. 3 is a view similar to Figs. 1 and 2 and showing a preferredembodiment of my invention as applied to a clinker pit having doubleclinker grinder rolls.

In the operation of grinder roll mechanism associated with combustionapparatus, I have found that agitation of the mass of refuse in a refusepit by the action of the grinder rolls effects a constant downwardsiftingofthe ner material in therpit and its final escape from the pitahead ofthe coarser material with which it is discharged into the pit.The line material discharged from the combustion apparatus andinto therefuse pit is com rised of a relatively high percentage of com ustiblewhich, due to the agitation of the larger clinker -masses, siftsdownwardly and outwardly of the pit before it has time to be consumed,with the result that the combustible content of the ash removed from theStoker represents a very material item of waste. I have found, byanalysis, that, with some coals, the combustible content of the ashremoved from the refuse pit may be as high as especially when the Stokeris being crowded.

Assuming a coal being burned in the Stoker havlng an ash content of 10%,if the combustible content of the ash is 40%, this would represent awastage of 4% of the total fuel passing through the furnace.

The wastage above referred to has been very greatly reduced, inaccordance with my invention, by the application of a shield beneath thegrinder roll or rolls whereby the fine material in the mass of refuse inthe pit is prevented from sifting from the pit and it may only beremoved by direct action of the grinder roll along with the heaviermasses of clinker which are being broken up by the rolls.A In this waythe finer material, when discharged into the pit together with largerclinker masses, remains associ-ated with the larger clinker masses inthe upper part of the pit until it is completely burned. By this means Ihave found that the percentage of the combustible in the ash may bereduced to a`s`low as 5%, which reduction it is apparent, effects a verymaterial saving in the fuel being burned by the stoker.

Referring to the drawings for a betterfunderstanding of my invention, Ishow, in Fig. 1 at 10, a progressive feed stoker which may be of anyapproved type, and which discharges into a clinker pit 11. The clinkerpit 11 is supplied with air for the combustion of the combustiblematerial of the ash from supplementary air boxes 12 and 13 arranged onopposite sides of the pit and discharging through suitable apertures 14and 16, respectively. Beneath the air boxes 12 and 13, there is suitablestructure defining clinker pit front and rear side walls 17 and 18,respectively, while at the bottom of the pit there is arranged a clinkergrinder roll 19 carried in'- suitable bearings 21 and actuated by anysuit-l able means (not shown) so as to rotate in the direction shown bythe arrow. The clinker grinder roll in being rotated serves to break upthe heavy mass of clinkers and discharges them from the clinker pitallin a manner well understood in the art to which my invention relates.f p

Heretofore, in the operation of apparatus so far described, the heavierclinker masses. being agitated by the clinker grinder roll 19 100 serveto agitate the whole mass of refuse within the clinker pit and cause adownward sifting of the line material in the ash and this tine materialwould sift out of the pit on both sides of the clinker grinder roll dueto the agitation, leaving the non-combustible heavy clinker masses inthe top of the pit. I have found that this undesired sifting of finematerial from the pit may be practically eliminated by the provision ofa shield member such as is shown at 22 beneath the clinker grinder rolland secured at 23 to that side of the clinker pit toward which theunderside of theroll is moving in rotation. The shield 22 should extendthe entire length of the clinker pit beneath the roll 19 and it iseffective to catch all iine material which would tend to sift downwardlypast the roll and cause it to be discharged in a predetermined path ofthe clinker pit 11 and only by the direct action of the roll 19.

Referring to Fig. 2, I show a clinker pit 26 having a pair of clinkergrinder rolls 27 and 28 arranged to be rotated by any suitablemechanism, not shown, in opposite directions as shown by the arrows.With this form of clinker grinder mechanism, there is a tendency forsiftings to pass forwardly and rearwardly of the rolls 27 and 28, whenthe rolls the being operated. I have found that this undesired siftingof line material may be practically eliminated by the provision of ashield 29 ext-ending transversely across and beneath the rolls 27 and 28and on Vwhich the fine material which first passes 'the rolls 27 and 28collects and eventually blocks further siftin thereby.

In ig. 3, I show a clinker pit 36 having clinker grinder rolls 37 and 38arranged similar to those shown in Fig. 2. In accordance with theshowing of Fig.- 3, the undesired siftings from the clinker pit 36 arepractically eliminated by the provision of a pair of shields 4l and 42.The shields 41 and 42 are connected respectively, to the rear and frontwalls 43 and 44 of the clinker pit 36 and the curve inwardly of the pitbeneath the rol s 37 and 38, so that a sin le path is presented for theremoval of ash j om the clinker pit. The line material which first siftspast the rolls 37 and 38 is caught on the shields 41 and 42 and furtherundesired is prevented. Thereafter the fine material discharged into theclinker pit 36 along with the heavier clinker masses is retained inassociation with' such masses until completely burned in the pit, andthe ash finally discharged from the pit hasa relatively low combustiblecontent.

From the foregoing, it will be apparent that I have devised an improvedapparatus for preventing the undesired siftings of fine material fromthe refuse pit of a combustion apparatus while in operation. j

While I have shown my invention as applied to a clinker pit which isarranged at the discharge end of a progressive underfeed Stoker, it isto be observed that in certain of its broader aspects it is not solimited; for it might equally as Well be applied to any 'refuse pitassociated with a combustion apparatus in which it is desired that thesifting of the finer material from the pit be minimized.

While I have shown my invention in but three forms, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various other changes and lmodifications vwithoutdeparting` from the spirit thereof, and we desire, therefore, that onlysuch limitations shall be placed vthere- Vupon as are imposed by theprior art or as disposed in spaced, substantially parallel relation withthe side wall of the pit; said grinder rollbeingprovided withprojections thereon for grinding the refuse out of said pit, and beingsupported for rotary motion in a direction to move the refuse away fromsaid side wall; and a shield member forming an extension of said sidewall and extending beneath the roll and beyond a vertical plane passingthrough the axis of said roll to provide a means for minimizing'thesifting of relatively fne particles of refuse from between the roll andthe side wall of the pit; a substantial part of the lower portions ofsaid shield being arranged in a substantially horizontal plane.

2. In .combustionapparatua the combina-I tion of a pit for receiving therefuse and including a pair of spaced, substantially parallel,upwardllxtending side walls; a pair of refuse grin g rolls disposedwithin the lower portion of said pit and being arranged in spaced,substantially parallel relation to one another; each of said rolls beingarran ed adjacent to and in spaced, substantial y arallel relation withthe lower portion od) one of the u wardly-extendn side walls of the pit;said grinding rolls eing provided with projections thereon for grindmgthe refuse out of the pit, and being supported for rotary motion indirections to move the refuse away from the side walls and to dischargethe refuse from between them; and shield members forming extensions ofthe side walls; each of said shield members having its respective lowerouter portion extending beneath its adjacent roll and beyond a verticalplane passing through the axis of said adjacent roll to provide a meansfor minimizing the sifting of relatively ne particles of refuse frombetween each roll and its adjacent side wall of the pit.

3. In combustion apparatus, the combination of a pit for receiving therefuse and including a pair of spaced, substantially parallel,upwardly-extending side walls; a pair of refuse grinding rolls disposedwithin the lower portion of said pit and being arranged in spacedsubstantially parallel rem lation to one another; each of said rollsbeing arranged adjacent to and in spaced, ysubstantially parallelrelation with the lower portion of one of the upwardly-extending sidewalls of the pit; said grinding rolls A bein 'provided with projectionsthereon for grin ing the refuse out of the pit, and being supported forrotary motion in directions to move the refuse away from the side wallsand to discharge the refuse from between them; and shield membersforming extensions of the side walls; each of said shield membersextending beneath its adjacent grinding rollv andbeyond a vertical planepassing through the axis of said adjacent roll to provide a means forminimizing the sifting of relatively ine particles of refuse frombetween said adjacent roll and its respective side wall; a substantialpart of the lower portion of each of said shields being arranged insubstantially horizontal planes.

In testimony whereof, I have hereunto subscribed my name this second dayof February, 1927.

ROBERT A. FORESMAN.

